In the field, an arborist after pruning a tree with his or her pruning saw typically places the saw back into a sheath or other saw holder connected to the arborist's belt. The tree just pruned may be infected with a disease, which may become disposed on the saw blade. If the arborist is unaware of such fact, the disease may remain on the saw blade when the arborist begins to prune a next tree. If the next tree is healthy, the use of the saw blade containing the disease by the arborist to prune such tree may cause the healthy tree to unknowingly become infected with the disease. It is to overcoming or reducing the occurrences of unintentionally infecting healthy trees with a disease during pruning that the present invention is directed.